1. Field
The present disclosure relates generally to control surfaces and, in particular, to control surfaces associated with aircraft structures. Still more particularly, the present disclosure relates to a method and apparatus for calibrating the transducers used to measure the angle formed at the interface between a control surface and a structure of an aircraft.
2. Background
An aircraft may have any number of control surfaces. As used herein, a “control surface” may be a device or structure that provides reactive force when in motion relative to the surrounding air. A control surface, which may also be referred to as a flight control surface, may lift or control an aircraft during flight. Examples of control surfaces include, but are not limited to, flaps, ailerons, horizontal stabilizers, vertical stabilizers, and other types of control surfaces.
A control surface, such as a flap or aileron, may be attached to the trailing edge of the wing of an aircraft. For example, the control surface may be attached to the wing using one or more hinges to form a hinged interface between the control surface and the wing. The control surface may be rotated about the hinged interface to change the lift generated for the aircraft and/or the motion of the aircraft.
One or more transducers may be used to measure the rotation of the control surface about the hinged interface. As one illustrative example, transducers may be positioned at the hinges connecting the control surface to the wing. These transducers may include, for example, position sensors, rotation sensors, and/or other types of sensors.
Each transducer may generate output values indicating the angle of rotation of the control surface about the hinged interface. However, these output values may not be in desired angular units, such as degrees. The output values generated by a transducer may be converted into angle values in desired angular units based on tables and/or mathematical equations correlating to the output values of a transducer to reference angles in the desired angular units. These tables may be created by, for example, the manufacturer of the transducer. The angle values identified may be used to determine control law for the flight control system of the aircraft and/or to verify control laws.
However, in some cases, the angle value identified may be different from the actual angle of rotation of the control surface. This difference may be the result of, for example, without limitation, the manner in which the transducer was installed at the hinged interface. Consequently, the transducer may need to be calibrated after installation to ensure that the correct angle values are being identified.
Some currently available methods for calibrating these transducers may be more difficult and/or time-consuming than desired. These methods may include using, for example, without limitation, mechanical protractors, accelerometers, pendulum mechanisms, inclinometers, and/or other types of devices to identify the actual angle of rotation of the control surface. However, using these devices may provide results that are less accurate than desired and may be more time-consuming than desired. Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues.